1. Field of the Invention
This invention relates to hydrocarbon-soluble compositions containing a transition metal salt of an organic acid and a hydrocarbon-soluble ashless dispersant. Typically, it relates to such compositions wherein the organic acid is a carboxylic, sulfonic or phosphorus acid and the ashless dispersant is a nitrogen or non-nitrogen containing ester dispersant. It also relates to hydrocarbon systems containing the aforesaid compositions, such as lubricants based on oils of lubricating viscosity and hydrocarbon fuels.
2. Prior Art
The treatment of hydrocarbon systems such as lubricants based on lubricating oils of lubricating viscosity (e.g., greases, lubricating oils and the like) and hydrocarbon fuels of both the solid and normally liquid type with transition metals and transition metal-containing compounds, both organic and inorganic, is well known to the art. Such treatments are used to increase the systems' resistance to oxidative deterioration, promote their conversion to cohesive films in the case of paints and lacquers, and improve their combustion as, for example, fuels.
Among the organic transition metal compounds that have been used for such purposes are carboxylate and sulfonate salts and mixtures of such salts. For example, U.S. Pat. No. 4,162,986 to Alkaitis et al. describes transition metal salts of mixed organic carboxylic and sulfonic or second carboxylic acids and their use as catalysts, anti-knock agents, combustion improvers, smoke suppressants, curing agents, driers, micronutrient sources, lubricant additives, and the like.
U.S. Pat. No. 3,762,890 to Collins describes hydrolyzable manganese soaps, stabilized by the inclusion of proprionic acid and the use of such materials as siccatives for paints, varnishes and inks, stabilizers in various plastics and additives for greases and lubricating oils as well as smoke-suppressing and anti-corrosion additives for fuel and fuel oils.
U.S. Pat. No. 3,723,152 to Alkaitis et al. describes basic cobalt salts of carboxylic acids and their use as drier compositions for oil vehicles.
Other patents such as U.S. Pat. No. 4,202,671 to Diehl et al. describe the use of organic magnesium compounds as fuel conditioners for the reduction of fuel requirements and emissions.
Increasing concern with pollution and the rising cost of hydrocarbon-based fuels and lubricants has promoted continued interest in the use of transition metal compounds in such systems. It has been found, however, that such uses sometimes causes deleterious as well as beneficial effects. Among the deleterious effects are promotion of sediment and sludge, particularly in lubricants and fuel oils. Such deposits can interfere with storage and transport of the oil by promoting corrosion and interfering with pumps, meters and associated equipment.
Therefore, it is an object of the present invention to provide hydrocarbon-soluble compositions containing organic transition metal salts in combination with ashless dispersants, which provide an optimum balance between beneficial and deleterious effects. Other objects will be apparent to those of skill in the art upon reading this disclosure.